1. Field of the Invention
The invention is in the field of re-fillable syringes for medication delivery and in particular is directed to an apparatus for automatically shielding a re-fillable syringe.
2. Description of the Related Art
The prior art teaches various safety shield systems adapted for use with a medication pen. Examples of passive shielding systems include U.S. Patent Application Publication Nos. 2011/0288491 and 2011/0257603, which are incorporated by reference. The needle assemblies disclosed in these publications include a patient-side needle for administering the injection, and a proximal side needle which extends into the medication compartment of the medication pen. In embodiments, the needle assembly includes a passive dual-shield for the patient end cannula which provides for passive protection of the cannula before and after use, as well as a passively activated shield for covering the proximal side needle to prevent accidental needle stick when the needle assembly is removed from the medication pen.
A similar passive shielding system is not available for a refillable syringe, which is delivered empty to the user and which must be filled from a vial. The shielded syringe designs that do exist rely on user manipulation, such as a hinged cover connected at the base of the needle which the user folds over the needle after use, or a linearly actuated shield which is pushed with the thumb or opposite hand after injection is complete. U.S. Pat. No. 7,101,351 to Crawford, et al., for example, which is incorporated by reference, teaches a shield for a syringe activated by distal movement of the syringe plunger after an injection is administered.
A passive two-shielded design has not heretofore been adapted for use with a refillable syringe. Thus, an object of the invention is to provide a dual-shielded design for use with a syringe.
A further object of the invention is to provide a passively shielded syringe with a vial adapter to permit filling the syringe from a vial without activating the passive shield system.